PREPARATION AND CHARACTERIZATION OF MgB[sub 2] BULK SAMPLES USING HIGH-ENERGY BALL MILLING AND HOT ISOSTATIC PRESSING

Development and Characterization of Cu–Nb–MgB2 and CuNi–Nb–MgB2 Wires With VB2 and Carbon Nanotube Additions

“…Testing these hypotheses and behaviors will be performed in the future with complete characterization of all samples, including microstructural and superconducting characterization. The influence of doping will be evaluated, together with previous work [3], [4], [6]- [9]. New heat treatments will be performed with argon flow.…”

“…The mixture of the MgB 2 powders with VB 2 and carbon nanotube were milled together for 300 minutes in a SPEX8000D high energy mill using tungsten carbide milling jar and balls. The ratio of ball to powder mass, was 3 : 1 [3], [4], [6], [7], [9]. All operations to prepare and mill the powder were performed inside an Ar atmosphere glove-box, that actively removed O 2 and water to avoid the formation of impurities and contamination, such as MgO.…”

“…VB 2 powder was added to the MgB 2 powder to obtain 5 at.% V doping (for Mg) [3], [4], [6], [7], [9], [14]- [17], and then 3 wt.% of carbon nanotubes (CNT) was added. The mixture of the MgB 2 powders with VB 2 and carbon nanotube were milled together for 300 minutes in a SPEX8000D high energy mill using tungsten carbide milling jar and balls.…”

“…Doping with compounds that have the AlB 2 -type structure was previously used and proved to be promising to increase the efficiency of flux pinning and improving the transport properties of the doped superconductors [6]- [9].…”

“…This paper presents preliminary results on the development of MgB 2 multifilamentary superconducting wires using the powder-in-tube (PIT) methodology and powders prepared with doping conditions developed in previous studies [3], [4], [6], [7], [9]. It describes a methodology to produce wires using MgB 2 powders containing additions of VB 2 and carbon nanotubes [6]- [12]. Addition of VB 2 can create artificial pinning centers (APC) in MgB 2 and conditions for doping vanadium on the magnesium sites [7], [13].…”